Abstract: Thin-layered method(TLM) is very efficient to study the wave propagation in layered ground,and boundary element method(BEM) is very precise to solve infinite domain problems.Combining the advantages of the above two methods,3D semi-analytical BEM model based on TLM was presented with the Green function as fundamental solution of stratified half-space.The effectiveness of active vibration isolation with 3D wave impeding block(WIB) in the upper stiff-layer and lower soft-layer was analyzed in detail.It was shown that the increase of thickness and modulus of WIB could increase effectiveness of isolation of ground vibration.It was found that the properties and thickness of layered soils significantly affected the screening effectiveness of ground vibration in radial and vertical directions.